This is my om617.952 running on a stand and i feel it has a weird idle. Any ideas what could be causing this?

In this video the garden hose was connected to it and I just ran 2 cans of diesel purge through it. At this point it was running on diesel again. Revs nicely and ran good in the car. The only other thing i can add is that i noticed the line going to the alda is missing.

Thanks for your input.

https://www.youtube.com/watch?v=krKBQ3_Z8c0